A well-defined cold front associated with a strong upper-level low produced widespread wind damage and a few tornadoes throughout central and eastern Minnesota and western Wisconsin on August 29th, 2024. Four tornadoes occurred.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS MPX wrote it up.
A well-defined cold front associated with a strong upper-level low produced widespread wind damage and a few tornadoes throughout central and eastern Minnesota and western Wisconsin on August 29th, 2024. Four tornadoes occurred. There were also a number of downbursts, with some of the most significant downburst damage in Champlin, Anoka, and Cottage Grove.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Twin Cities, MN wrote its last area forecast discussion before the first event at Aug 29, 11:54 AM CST, 1 hour 38 minutes earlier. Its key messages:
Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 1254 PM CDT Thu Aug 29 2024 .KEY MESSAGES... - Enhanced Risk (level 3 of 5) of severe storms this afternoon and evening. - Pleasant Labor Day weekend, with no major systems expected through early next week. && .UPDATE... Issued at 1240 PM CDT Thu Aug 29 2024 After collaboration with the SPC, much of our CWA was upgraded to an Enhanced Risk (level 3 of 5) for severe storms this afternoon and evening. The main driver of this upgrade is the damaging wind potential, but the risk for a few tornadoes and large hail also exists, particularly across central Minnesota near the triple point of the low. While today's storms may not be quite as strong as Monday's round of severe weather that brought +70 MPH winds to parts of the CWA, our confidence in timing, coverage, and storm mode is higher for today. The timing of the strongest storms still remains on track to develop sometime between 3-4pm across western/central Minnesota before growing upscale and marching eastward. They are expected to reach the Twin Cities metro between 5-7pm and continue into western Wisconsin from 7pm-10pm. && .DISCUSSION... Issued at 240 AM CDT Thu Aug 29 2024 Although it was a spectacular evening on Wednesday and the night has been rather uneventful for us, things are changing... Water vapor imagery and RAP h5 analysis shows an impressive mid-level low spinning across the MT/Canada border this morning. In response to the height falls ahead of it, we've seen a strong LLJ and push of rich theta-e air surge north across the Dakotas. The nose of the strongest WAA within this LLJ has helped generate the thunderstorm activity we've seen overnight across NoDak. This upper low and strong WAA will all track toward northwest Ontario through the day, which means the activity we have seen overnight over NoDak will remain north of the MPX area. However, as the upper low continues to the east, we will see the warm front currently across eastern SoDak and northern Iowa surge north across the area through the morning. The main impact from this warm front surging north across the area this morning is that we will have extensive stratus develop out ahead of it from southeast into central MN and across western WI. In the wake of this warm front though we will see another warm and humid airmass advect into the region, with highs expected to be in the mid/upper 80s and dewpoints in the low to mid 70s out ahead of a cold front that will be moving into western MN this afternoon. Looking at the severe potential today, what will not be lacking is instability, with the temp/dewpoint combo mentioned above sending mlCAPE values up to between 3000 and 4000 j/kg this afternoon. What we're lacking in the severe parameter space is shear. The mid-level jet will be up near the h5 low, with deep shear this far south being near 30 kts. Looking at hodographs, you see a further issue. Though we have good shear and curvature in the lowest 2 km of the hodographs, there is a weakness in the flow between 2 and 6 km, where the hodographs loop back on themselves. Given this setup, you tend to struggle to maintain prolonged strong updrafts with the weak mid-level flow causing limited tilt in the updrafts. Though the parameters do support supercells, bulk shear vectors roughly parallel to the front means we will trend toward a linear mode rather quickly after initiation, which is what we see when looking at CAM reflectivity outputs. Given all of that, a Slight Risk (level 2 of 5) from the SPC for today's threat looks reasonable, with a typical August severe setup, with the hail and brief tornado threat most likely at initiation, with a transition to a heavy rain and wind threat as storms grow upscale. The excessive rain threat looks isolated at best. We'll have convection with PWATs just under 2", but storm motion looks sufficient to really limit any sort of widespread excessive rain threat with storms today. As for timing, storms are currently expected to fire around 19z (2pm) in western MN (in the neighborhood of places such as Granite Falls, Willmar, and Long Prairie). Storm will go linear pretty quick, with this initial line coming through Twin Cities metro between 21z and 0z (4pm-7pm), moving across our WI counties between 00z and 3z (7pm to 10pm). There are some indications of a second area of storms developing behind this primary activity on the cold front itself, but this activity looks to have limited severe potential and would just help to add to rain totals. As for rainfall, most areas that see rain will see a half to three-quarters of an inch, with a few pockets of 1-2 inches possible if a location can double dip into both potential rounds of storms. After this front moves through, the weather will be very quiet through the first half of next week. We will see a strong and dry cold front drop across the upper MS Valley on Saturday, which will bring us a fall preview Sunday and Monday, with dewpoints down in the 40s, highs in the low 70s and lows on Monday morning dropping into the 40s for all but the urban core of the Twin Cities metro area. Southerly flow quickly returns on Tuesday, which will push temperatures back closer to normal by the middle of next week. Though we will see increased temperatures and dewpoints with that southerly flow, there will be split flow aloft and we look to be stuck in the middle, so there will be little forcing for any additional precipitation. && .AVIATION /18Z TAFS THROUGH 18Z FRIDAY/... Issued at 1240 PM CDT Thu Aug 29 2024 The IFR/MVFR stratus deck has shifted NE, but will still impact the western Wisconsin sites for the early afternoon. A pocket of clearing is visible over much of central Minnesota, while convection is becoming more widespread along the western MN border. As the front sags southeast, a period of heavy rain and convective wind gusts will likely impact each site. Behind the line, cigs will quickly rise and winds will weaken and shift out of the NW. There is a chance for low stratus and patchy fog for some locations overnight, especially over western Wisconsin. KMSP...Timing is still on track, so not too much change for the ongoing TAF. Scattered storms could arrive ahead of the front around 20z, with the main line moving through close to 21-23z. Some models indicate that more isolated storms storms could fill in behind the main line, so we have maintained the tempo through 01z for now. /OUTLOOK FOR KMSP/ SAT...VFR. Wind SW 10-15kts. SUN...VFR. Wind N 5-10kts. MON...VFR. Wind S 5-10kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && UPDATE...Dye DISCUSSION...MPG AVIATION...BED
Hazardous Weather Outlook National Weather Service Twin Cities/Chanhassen MN 349 AM CDT Thu Aug 29 2024 MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028- 300900- Douglas-Todd-Morrison-Mille Lacs-Kanabec-Stevens-Pope-Stearns- Benton-Sherburne-Isanti-Chisago-Lac Qui Parle-Swift-Chippewa- Kandiyohi-Meeker-Wright-Hennepin-Anoka-Ramsey-Washington- Yellow Medicine-Renville-McLeod-Sibley-Carver-Scott-Dakota- Redwood-Brown-Nicollet-Le Sueur-Rice-Goodhue-Watonwan-Blue Earth- Waseca-Steele-Martin-Faribault-Freeborn-Polk-Barron-Rusk- St. Croix-Pierce-Dunn-Pepin-Eau Claire- 349 AM CDT Thu Aug 29 2024 This Hazardous Weather Outlook is for portions of central and southern Minnesota, and west central Wisconsin. .DAY ONE...Today and Tonight. A slight risk for severe thunderstorms is present this afternoon and evening, with damaging wind and large hail the primary threats with a few tornadoes possible. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... SKYWARN spotter activation may be needed.
The Minneapolis radar (KMPX), 123 km away, was scanning. The volume nearest the first event began at 19:32 UTC.
27 thunderstorm wind, 6 tornado, 1 hail. Local standard time, as filed.
Large branches were down on the southwest side of Willmar.
County Dispatch reported trees down near the intersection of Co Rd 21 and 611th ave.
Multiple downed trees blocked roads throughout New Ulm.
County dispatch reported a tree down near the intersection of Hwy-24 and 285th St.
Boat lift bent as well as 12 oak trees down on the property.
Photo provided of telephone wire pole down.
Several 8-to-14-inch diameter tree limbs down.
Multiple trees up to two feet in diameter were toppled throughout the Pierz Trailer Park.
The tornado hit several farms before moving into Lastrup and dissipating. It ripped most of the roof off of two barns west and northwest of Pierz, then continued northeast to Lastrup, where it knocked down or broke large limbs of dozens of trees and tore off half of the roof of an outbuilding. Drone video from the Sheriff's Office showed a convergent damage pattern in Lastrup, and the damage survey showed a convergent pattern at several locations before the tornado hit Lastrup.
Damage to barn and outbuildings.
County dispatch reported trees down in Norwood Young America.
Tree down and power line down blocking one lane of Hwy 5 near the Arboretum east of Victoria.
County dispatch reported light pole down in Albertville.
Two birch trees and several tree branches down in Maple Grove.
Photo via social media of multiple large trees uprooted near Dean Ave and Cartway Rd.
Dozens of trees were broken or uprooted, in a pattern consistent with a downburst.
A storm survey was performed and drone video from the Sheriff's Office was viewed to determine that this part of Anoka was hit by a downburst. Over 100 trees were broken or uprooted, some of which fell on houses, sheds, and vehicles.
Report via social media of multiple large trees uprooted in the Cutter's Grove area near Hwy 10.
Photo report via social media of multiple large trees snapped.
Photo report via social media of large tree uprooted.
Photo of large tree down measuring 22 inches in diameter.
Tornado developed in the northeast corner of Andover and continued north-northeast into the southeast portion of Oak Grove, where it dissipated. Hundreds of trees were broken or uprooted, some of which fell on houses, sheds, and vehicles. In addition to performing a storm survey, drone video from the Sheriff's Office was viewed.
A tornado developed in the northeast corner of Oak Grove, tracked across the southeastern part of St Francis, then into East Bethel. The tornado continued northeast into Isanti County. In Anoka County, hundreds of trees were broken or uprooted, some of which landed on houses, sheds, and vehicles. Part of a roof was blown off a machine shed at a farm.
County dispatch reported a power line down near the intersection of Webster Ave and Center St.
A tornado developed in Anoka County and moved through portions of Oak Grove, St Francis, and East Bethel before crossing into Isanti County. In Isanti County, two farm outbuildings were destroyed and a pole barn sustained roof damage. Hundreds of trees were also broken or uprooted.
Trees measuring 8 inches in diameter snapped halfway up from the base near Cty Rd 5 and Durant St. East of Isanti.
Photo provided via social media of snapped maple tree.
Photo provided via social media of significant tree damage near Jefferson Trail NW and South Robert Trail in Eagan.
Multiple large trees down with some landing on power lines and resulting in power outages across north Faribault.
Damage to shed along with multiple trees blown over and uprooted in the neighborhood.
A tornado developed at the southern edge of Bellwood Oaks Golf Course, uprooting several trees, then continued northeast. A narrow path of sporadic tree damage occurred along the track, with the last damage in Minnesota being on Blackbird Trail in Dakota County. The tornado tracked across a sliver of northern Goodhue County before crossing the Mississippi River into Wisconsin, dissipating about 5 miles southeast of Prescott in Pierce County.
A tornado developed at the southern edge of Bellwood Oaks Golf Course, in Dakota County. It moved northeast and tracked across a sliver of northern Goodhue County before crossing the Mississippi River into Wisconsin, dissipating about 5 miles southeast of Prescott in Pierce County.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Minnesota in 2024Every state in 2024This day in weather historyThe tornado archive for Minnesota, 2024Warnings in Minnesota, August 2024
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1211894, 1211871, 1211985, 1211890, 1211899, 1211904, 1212014, 1211887, 1211915, 1211047, 1211921, 1211988, 1211863, 1212004, 1212021, 1212007, 1212008, 1211106, 1211107, 1211967, 1211968, 1211974, 1212023, 1211108, 1211109, 1211878, 1211110, 1212566, 1212558, 1212562, 1212635, 1212636, 1201033, 1201040.